Bury tool co



H. D. WILLIAMS. BACK PRESSURE RELEASE VALVE. APPLICATION FILED AUG-2!, 191s.

2 SHEETSSHEET I.

Patented June 24, 1919.

H. D. WILLIAMS.

BACK PRESSURE RELEASE VALVE.

APPLICATION FILED AUG-21.19I'8.

Patented June 2 1919. 7

2 SHEETS-SHEET 2.

BURY TOOL ('10., OF WATER/BURY, CONNECTICUT, A CORPORATION.

BACK-PRESSURE RELEASE-VALVE.

Specification of Letters Patent. Patented J 11 24 1919, I

Application filed August 21, 1918. Serial N 0. 250,840.

To all whom it may concern:

Be it known that I, HARVEY D. WILLIAMS,

a citizen of the United States, residing at VVallingford, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Back-Pressure Release-Valves; and I do hereby declare the following, when taken in connection with the accompanying drawings and the charactersof reference marked thereon,

to be a full, clear, and exact description of the same, and with said drawings constitute part of this application, and represent, in

Figure 1 a diagrammatic View illustrating the location of my improved back-pressure release valve with relation to a pump,-

hydraulic motor, and oil-expansion tank.

Fig. 2 a vertical sectional view of .the

release valve.

Fig. 3 an end view of the same.

F 1g. 4 a sectional view on the l1ne 44 of Fig. 2.

Fig. 5 a sectional view of a rotary, vari- In illustrating my invention, I have shown it .in connection with a double actin hydraulic motor which is controlled by a pump, which in turn is operated by a motor or other engine. In carrying out my invention, ,I employ a back-pressure release valve 5 the ends of which are connected by pipes 6 and 7 with pipes 8 and 9 which lead from a rotary variable stroke reversible flow hydraulic pump 10,such, for instance, as is shown in U. S. PatentNo. 1,020,285, to opposite cylinders 11 and '12 of a hydraulic motor. The pump- 10 consists as shown in Fig. 5 of'the drawings, of a casing'having the inner chamber 32 closed at one end and supported by suitable legs 33. The casing 32 is provided at one end with a bearing 34 for a revoluble shaft 35, the opposite end of which is provided with a reduced end 36 having a bearing in the end ing a part of the casing 32. ounted upon each provided .be moving outwardly in piate 37 formand revoluble with the shaft 35 is a cylinder barrel 38 having a plurality of cylinders 39 with a port 40, which ports are of less area than the area of the respective cylinders and are preferably lengthened in the direction of rotation. In each of the cylinders 39 is mounted a piston 41 to which,

is pivotally attached a connecting rod 42,

' HARVEY D. WILLIAMS, 0F WALLINC-FORD, CONNECTICUT, ASSIG-NOR TO THE WATER- the opposite end of which is provided with a spherical head 43 mounted in a suitable socket 44 in a ring 45. The ring 45 is provided with diametral trunnions 46 mounted in sockets formed in a ring47 pivotallyconnected to the revoluble shaft 35 by apin 48 at right angles to the said trunnions 46.

By this construction the ring 45 is univer- .sally connected to the shaft 35 and can readily tilt in either direction during its rotation about the axis of the shaft 35. During this rotation it is obvious that should the for instance, that shown in Fig. 5 of the drawings, the rotation of the shaft 35 will cause the pistons 41 to reciprocate in the cylinders 39 and as the rotation of the ring 45 and the cylinder 38 are coincident the ports 40 will be moved successively into positions opposite the port to the inlet 8, then opposite the port to the outlet 9.

he pipes 8 and 9 communicate with the cylinders 39, and as the ports 40 are passing the port to the inlet pipe 8 the pistons 41 will drawing the fluid into said cylinder, which in the travel of the'cylinder barrel 38 about Illlg'be tilted to any desired inclination as,

the cylinder 39,.and

the axis of the shaft 35 will be carried into the position opposite the port to the inlet.

pipe 8 and by this time the piston will commence to move toward the ports 40' and the fluid-contained in the cylinders 39 will be forced through the ports into the outlet pipe 9. Within the chamber 32 is pivotally mounted a support or box 49 and end thrust and radial thrust is taken u by providing the box 49 with a fixed ring 50, having 'an inclined roller path on which is adapted to travel a plurality of conical rollers 51, said rollers being also provided with another roller path 52 upon a ring 53 carried by the ring 45.-'- This ring 53 is provided with two annular flanges 54 adapted to coincide with the truncated ends 56 of the conical rollers 51. These annular flanges 54 serve to retain the rollers radially within their prescribed path and in some cases, owing to the tendency of the rollers to move outwardly, the outer flange will be suflicient to accomplish this purpose.

The rollers 51 are mounted in a cage including a ring 57 having a plurality of radial extensions to the outer ends of which is secured a ring 59. These radial members have their opposed walls concaved forming pockets adapted to receive a conical roller 51. When the rollers have been positioned within said pockets and the ring 59 secured to the ends of the radial members, the rollers 51 are prevented from becoming accidentally displaced. The concaved walls insure the retention of the rollers 51 in positions with their axes radial to the center of the cage 5 -5-9.

The periphery of the ring 53 is provided with a shallow groove forming a track for a plurality of anti-friction members 61, preferably spherical, said members being mounted in a cage 62. These members 61 travel in the shallow groove in the periphery of thering 53 and in their travel bear against the inner face of the ring 63 carried by the tilting box 49. These members 61 sustain the radial thrust to which the ring 45 is subjeeted and retain said ring 53 and its supporting box 49 in coaxial relation to each other. The box or support 49 may be moved to any desired angle by a control shaft 64. The pump is driven by an electric motor or other engine 13 and connected with the pump 10 by a pipe 14 is an oil expansion tank 15. This pipe 14 is also coupled by a pipe 16 with the top of the back-pressure release valve 5. This back-pressure'release valve 5 comprises a casing 17 with a central annular channel 18 into which the pipe 16 opens. The ends of the casing are closed by plates 19 and 20, the plates having central openings 21 and 22 with which the pipes 6 and 7 are coupled. In opposite ends of the casing are chambers 23 and 24, and longitudinally mov able in the casing and guided by bearings 25 and 26, is a longitudinally movable piston 27 formed with longitudinal ports or grooves 28. Secured to opposite ends of the piston are heads 29 and 30, these heads being held in place against opposite ends of. the piston bya bolt 31. The length ofthe piston is somewhat longer than the distance between the outer faces of the bearings 25 and 26 so that when either of the heads 29 and 30 are seated at one end a passage is formed at the.

opposite end to the annular groove 18, and from thence to the pipe 16. This ,piston is moved back and forth accordingly as the double ended plunger 32 is moved back and forth by the circulation of liquid through the pipes 8 or 9. As the double acting plunger is forced into one cylinder or the other, the pressure of oil in the pipe 9 will force the head 30 to its seat so as to close the flow of oil through the release valve and permit any surplus oil passing through the pipe 8 to enter the chamber 23 in the valve and pass through one of the ports 28 to the annular groove 18, and from thence through the pipe 16 to the oil expansion tank. When pressure is applied on the opposite side, the piston is reversed in position, and the device operates to relieve any pressure in the pipe 9. A better circulation of liquid is thus obtained and the pressure in the cylinders 11 and 12 relieved as required. It sometimes occurs that air may enter the circulatory system, and if so, it will find its way out through the oil expansion tank, and in this way also, improve the efliciency of a hydraulic motor.

I claim v 1. The combination with a hydraulic motor, a pump connected with opposite ends of the motor and an oil expansion tank connected with said pump, of a back-pressure release Valve located between the pump and the hydraulic motor, said pump comprising a casing connected with opposite sides of the pump and with the oil expansion tank, said release valve comprising a casing, a longitudinally movable piston, heads on the opposite ends of the piston,seats for said heads, said piston formed with longitudinal ports, said casing also formed with an annular groove intersected by said port, said groove communicating with the oil-expansion tank.

2. The combination with a hydraulic motor, a rotary variable stroke reversible flow hydraulic pump, and fluid expansion tank, said pump and motor permanently connected by fluid passages forming a closed circulatory hydraulic system, and a release valve connected with the fluid passages and the expansion tank and adapted to maintain a free fluid assage from the low pressure side of the hy raulic system.

I i-testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

HARVEY D. WILLIAMS. 

